ASTM vs EN vs BS Pipe Equivalents

Quick Reference

This guide provides cross-reference tables between American (ASTM/API), European (EN), and British (BS) pipe specifications. Whether you’re sourcing materials globally, verifying MTCs, or converting specs for international projects, scroll to the matching tables below to find equivalent grades for carbon, alloy, stainless, and nickel alloy pipes.

Key Pipe Specs (US/EU/UK)

Pro Tip

“Equivalent” grades aren’t always interchangeable. ASTM A312 TP316L and EN 1.4404 have similar compositions but different testing requirements - the EN spec may not include the corrosion testing your ASME code requires. When substituting, verify both chemical composition AND mechanical/testing requirements meet your design code.

American Pipes Specifications

If you work primarily with US-based suppliers or projects following ASME codes, you’ll encounter ASTM and API specifications daily. These standards-developed by ASTM International and the American Petroleum Institute-cover everything from commodity carbon steel to exotic nickel alloys.

Carbon Steel Pipes

Spec	Description
ASTM A53/A53M	Seamless and welded black/galvanized pipe
ASTM A106/A106M	Seamless pipe for high-temperature service
ASTM A333/A333M	Seamless and welded pipe for low-temperature service
API 5L	Line pipe for petroleum/natural gas pipelines

Alloy Steel Pipes

Spec	Description
ASTM A335/A335M	Seamless ferritic alloy pipe for high-temperature service
ASTM A691/A691M	Electric-fusion-welded pipe for high-pressure/high-temperature

Stainless Steel Pipes

Spec	Description
ASTM A312/A312M	Seamless, welded, and cold-worked austenitic pipes
ASTM A358/A358M	Electric-fusion-welded austenitic pipe for high-temperature

Duplex and Super Duplex Steel Pipes

Spec	Description
ASTM A790/A790M	Seamless and welded ferritic/austenitic pipe
ASTM A928/A928M	Duplex pipe, electric-fusion-welded with filler metal

Nickel Alloys

Spec	Description
ASTM B161	Nickel seamless pipe and tube
ASTM B622	Seamless nickel and nickel-cobalt alloy pipe
ASTM B444	Inconel 625 (UNS N06625) pipe and tube

Non-Ferrous Pipes

For copper, aluminum, and titanium, standards are material-specific:

Spec	Description
ASTM B88	Seamless copper water tube
ASTM B241/B241M	Aluminum seamless pipe and extruded tube

European Pipes Specifications

European standards (EN) developed by CEN follow a logical numbering system: the EN 10216 series covers seamless tubes, while EN 10217 covers welded tubes. The suffix number indicates the material category.

Carbon Steel Pipes

Spec	Description
EN 10216-1	Seamless tubes, non-alloy steel, room temperature properties
EN 10217-1	Welded tubes, non-alloy steel, room temperature properties

Alloy Steel Pipes

Spec	Description
EN 10216-2	Seamless tubes, non-alloy and alloy steel, elevated temperature
EN 10217-2	Welded tubes, non-alloy and alloy steel, elevated temperature

Stainless Steel Pipes

Spec	Description
EN 10216-5	Seamless stainless steel tubes for pressure purposes
EN 10217-7	Welded stainless steel tubes for pressure purposes

Duplex and Super Duplex Steel Pipes

Duplex grades fall under the stainless steel categories above. The most common grade, EN 1.4462 (equivalent to ASTM 2205), appears in the EN 10088 material series.

Nickel Alloys

EN nickel alloy standards tend to be material-specific rather than consolidated. Most European projects reference ASTM specs for nickel alloys, with the Werkstoff number serving as the cross-reference.

Non-Ferrous

Spec	Description
EN 1057	Seamless copper tubes for water/gas (sanitary and heating)
EN 754	Aluminum cold-drawn rod, bar, and tube

British Pipes Specifications

Since the UK adopted European Norms, most BS standards now carry the “BS EN” prefix-they’re essentially EN standards with British recognition. However, a few legacy BS specs (like BS 1387) still appear on older drawings and in established supply chains.

Carbon Steel Pipes

Spec	Description
BS 1387	Screwed/socketed steel tubes for gas and water (legacy)
BS EN 10255	Non-alloy tubes for welding/threading (replaced BS 1387)

Alloy Steel Pipes

Spec	Description
BS EN 10216-2	Seamless alloy tubes for elevated temperature
BS EN 10253-2	Butt-welding fittings, alloy steels with inspection

Stainless Steel Pipes

Spec	Description
BS EN 10216-5	Seamless stainless steel tubes
BS EN 10217-7	Welded stainless steel tubes

Duplex, Nickel Alloys, and Non-Ferrous

UK standards for these materials are fully harmonized with EN standards. You’ll reference the same EN specs listed above, with the BS EN prefix indicating British adoption. For copper, BS EN 1057 remains the go-to standard for plumbing and heating applications.

Canadian Pipes Specifications

Canadian Standards Association (CSA) develops specs tailored to Canada’s extreme climates and oil sands industry. In practice, Canadian projects heavily reference ASTM standards, with CSA standards serving as overlays for specific applications.

Spec	Application
CSA Z245.1	Steel line pipe for petroleum/gas pipelines (harsh climate conditions)
CSA B51	Boiler, pressure vessel, and pressure piping code
CSA B88	Seamless copper water tubes (plumbing, heating, cooling)

For specialty materials-stainless, duplex, nickel alloys-Canadian projects typically reference ASTM or EN standards directly. The oil sands industry commonly specifies ASTM B444 (Inconel 625) for high-corrosion environments.

Field Note

When sourcing from European mills, get comfortable with Werkstoff numbers - they’re the universal identifier in EU manufacturing. The Werkstoff number (like 1.4404 or 2.4856) uniquely identifies the material regardless of which EN or DIN standard is referenced. Keep a cross-reference handy; mills often mark products with Werkstoff numbers even when the order specifies ASTM grades.

When working across international projects, always verify that “equivalent” grades meet both chemical composition AND mechanical/testing requirements of your design code. A certificate showing only the EN grade when your PO specifies ASTM may be rejected by QC; request dual-certified material or an MTC explicitly stating compliance with both standards.

Pipe Specs Matching Tables

The tables below provide direct cross-references between US and EU specifications. Use these when converting material requirements between projects, verifying MTCs, or sourcing equivalent materials from different regions.

Common Mistake

Accepting an MTC showing only the EN grade when your PO specifies ASTM. Even if the grades are equivalent, the MTC must reference the standard you ordered. A certificate showing “1.4404” when you ordered “A312 TP316L” may be rejected by your client’s QC - request dual-certified material or an MTC explicitly stating compliance with both standards.

Carbon Steel Pipes

Application	US Spec	EU Spec	US Grades	EU Grades
High-temperature	API 5L	EN 10225	B, X42, X52, X60, X65, X70, X80	S355G15, S460G6
General Purpose	ASTM A53/A106	EN 10216-2 (Seamless)	Grade A, B, C	P235GH, P265GH
		EN 10217-5 (Welded)		P235GH, P265GH
Mechanical Tubing	ASTM A519	EN 10210	SAE 4130, 4140	S355J2H
Piling	ASTM A252	EN 10219	Grade 2, 3	S235, S355
Low Temperature	ASTM A333	EN 10216-3	Grade 1, 3, 6	P355N, P355NH, P275NL
Pressure Vessels	ASTM A671/A672	EN 10217-2	Grade 60, 65, 70	P235GH, P265GH

Alloy Steel Pipes

Application	US Spec	EU Spec	US Grades	EU Grades (Werkstoff)
High Temp/Pressure (Seamless)	ASTM A335	EN 10216-2	P1, P5, P9, P11, P22, P91, P92	16Mo3 (1.5415), 13CrMo4-5 (1.7335), 10CrMo9-10 (1.7380)
High Temp/Pressure (Welded)	ASTM A691	EN 10217-5	1-1/4CR, 2-1/4CR, 5CR, 9CR	16Mo3 (1.5415), 13CrMo4-5 (1.7335), X10CrMoVnb9-1 (1.4903)

Stainless Steel Pipes

US Specs: ASTM A312/A358 (Austenitic), ASTM A790/A928 (Duplex) EU Specs: EN 10216-5 (Seamless), EN 10217-7 (Welded)

Austenitic Grades

ASTM Grade	UNS	EN Grade	Werkstoff
304	S30400	X5CrNi18-10	1.4301
304L	S30403	X2CrNi19-11	1.4306
304H	S30409	X6CrNi18-11	1.4948
309S	S30908	X12CrNi23-13	1.4833
310	S31000	X15CrNiSi25-21	1.4841
310S	S31008	X8CrNi25-21	1.4845
316	S31600	X5CrNiMo17-12-2	1.4401
316L	S31603	X2CrNiMo17-12-2	1.4404
316H	S31609	X6CrNiMo17-13-3	1.4436
316Ti	S31635	X6CrNiMoTi17-12-2	1.4571
317L	S31703	X2CrNiMo18-15-4	1.4438
321	S32100	X6CrNiTi18-10	1.4541
321H	S32109	X8CrNiTi18-10	1.4878
347	S34700	X6CrNiNb18-10	1.4550
347H	S34709	X8CrNiNb16-13	1.4961
6Mo (254 SMO)	S31254	X1CrNiMoCuN20-18-7	1.4547
904L	N08904	X1NiCrMoCu25-20-5	1.4539

Duplex & Super Duplex Grades

ASTM Grade	UNS	EN Grade	Werkstoff
Lean Duplex 2101	S32101	X2CrMnNiN21-5-1	1.4162
Duplex 2304	S32304	X2CrNiN23-4	1.4362
Duplex 2205	S31803 / S32205	X2CrNiMoN22-5-3	1.4462
Duplex	S31260	X2CrNiMoN25-7-4	1.4410
Super Duplex 2507	S32750	X2CrNiMoN25-7-4	1.4410
Super Duplex	S32760	X2CrNiMoCuWN25-7-4	1.4501
Super Duplex	S32550	X2CrNiMoCuN25-6-3	1.4507

Nickel Alloy Pipes

US Specs: ASTM B161, B165, B167, B407, B423, B444, B622, B729 (Seamless); ASTM B464, B514, B517, B619, B705, B725 (Welded) EU Specs: EN 10216-5, EN 10217-7

Alloy	ASTM Seamless	ASTM Welded	UNS	DIN	Werkstoff
Alloy 20	B729	B464	N08020	-	2.4660
Nickel 200	B161	B725	N02200	Ni99.2	2.4060
Nickel 201	B161	B725	N02201	LC-Ni99	2.4061
Monel 400	B165	B725	N04400	NiCu30Fe	2.4360
Monel K-500	B865	-	N05500	NiCu30Al	2.4375
Inconel 600	B167	B517	N06600	NiCr15Fe	2.4816
Inconel 601	B167	B517	N06601	NiCr23Fe	2.4851
Inconel 625	B444	B705	N06625	NiCr22Mo9Nb	2.4856
Inconel 718	B637	-	N07718	NiCr19Fe19Nb5Mo3	2.4668
Incoloy 800	B407	B514	N08800	X10NiCrAlTi32-21	1.4876
Incoloy 800H	B407	B514	N08810	X10NiCrAlTi32-21H	1.4958
Incoloy 800HT	B407	B514	N08811	X8NiCrAlTi32-21	1.4959
Incoloy 825	B423	B704	N08825	NiCr21Mo	2.4858
Hastelloy B-2	B622	B619	N10665	NiMo28	2.4617
Hastelloy B-3	B622	B619	N10675	NiMo29Cr	2.4600
Hastelloy C-4	B622	B619	N06455	NiMo16Cr16Ti	2.4610
Hastelloy C-22	B622	B619	N06022	NiCr21Mo14W	2.4602
Hastelloy C-276	B622	B619	N10276	NiMo16Cr15W	2.4819
Hastelloy C-2000	B622	B619	N06200	NiCr23Mo16Cu	2.4675
Hastelloy G-30	B622	B619	N06030	NiCr30FeMo	2.4603
Hastelloy G-35	B622	B619	N06035	NiCr33Mo8	2.4643
Alloy 59	B622	B619	N06059	NiCr23Mo16Al	2.4605